Review on 🔋 Hembisen CO Detectors Alarm 3 Pack - Battery Powered Carbon Monoxide Detector with Digital Display for Home, Easy Installation, UL2034 Compliant by Eddie Man

Bought three packs and installed them in my pantry while waiting to brew beer in a semi-enclosed area (I have a garage-sized door and a massive storage fan for ventilation). I never bothered to brew beer when I installed these three sensors on my ceiling and let them run for about a month. After 3 weeks everything started to chirp. Okay, I replaced the batteries. After replacing the batteries with new AA batteries, one of them started warning that there was 175ppm in the area. The other two, about five feet to either side, didn't notice. OK. Bad batteries. Replace with another fresh set. The same thing. This time I took the device outside, put the batteries back in and held down the "working mode" button on the back to see if the device beeped. And so it was. A third false alarm also reads 174ppm outside in my backyard 50ft from my house. My conclusion is that these devices DO NOT WORK PROPERLY. If they are falsely reporting 174ppm outside, that means they are not falsely reporting 0ppm indoors. PLEASE DO NOT TRUST THIS DEVICE. YOUR LIFE CAN DEPEND ON IT BUY THE BEST BRAND!